Abstract: Objective To investigate the presence of bacteria in semen,strain distribution,bacterial resistance and the effects of bacterial infection on sperm analysis parameters. Methods The semen analysis,culture,identification and drug sensitivity tests were performed in 325 cases of masculine sterility in our hospital,and their influence on the sperm analysis parameters (sperm concentration,survival rate,and forward movement ratio and liquefaction time) was evaluated. Results A total of 127 strains of bacteria were isolated among 325 cases of male infertility with an infection rate of 39.1%,including G⁺ cocci (59.9%,mainly Staphylococcus aureus) and G^- bacilli (22%,mainly Escherichia coli).Drug sensitivity analysis showed that cephalosporins and macrolides resistance in staphylococcus was high;Ampicillin and Cotrimoxazole resistance in Escherichia coli was high.The sperm concentration in Neisseria gonorrhoeae group were significantly lower than that in the other infection groups (P<0.01);The survival rate of sperm in the Staphylococcus aureus and Escherichia coli group was significantly lower than those in the other infection groups (P<0.01);The difference in the rate of forward movement were found in Staphylococcus aureus,Escherichia coli and Neisseria gonorrhoeae group when compared with the other infection groups (P<0.01).The liquefaction time in the Escherichia coli group was longer than that of the other infection groups. Conclusion The positive rate of G⁺ cocci was higher than that of E.coli in bacterial culture of semen in male infertility patients;the effects of coagulase negative staphylococcus aureus,staphylococcus aureus,E.coli and gonorrhea neisseria bacteria on the semen analysis parameters has the characteristic respectively,and needed to be concerned.